The ten original studies included in this Research Topic investigate selected assumptions and predictions of parochial altruism theory in detail. We, the editors, are convinced that their highly instructive findings will help researchers interested in parochial altruism, but also in intergroup psychology more generally, to gain a much more fine-grained understanding of the interplay of altruistic and spiteful motives in human decision making in the context of intergroup relations. The broad range of disciplines represented by the authors contributing to this (...) Research Topic and the variety of methods used in their studies are representative for the current interdisciplinary interest in parochial altruism. The most important insight that, in our view, can be derived from the works collected here is that human decision making in intergroup contexts is more complex than suggested by current theory. Thus, we hope that future theorizing on parochial altruism will be stimulated by the evidence gathered in this Research Topic. In this editorial, we briefly highlight central findings reported here, which, to us, appear most informative for prospective enhancements of parochial altruism theory. (shrink)

In this article I develop a big picture of the evolution of human cooperation, and contrast it to an alternative based on group selection. The crucial claim is that hominin history has seen two major transitions in cooperation, and hence poses two deep puzzles about the origins and stability of cooperation. The first is the transition from great ape social lives to the lives of Pleistocene cooperative foragers; the second is the stability of the social contract through the early Holocene (...) transition to complex hierarchical societies. The first of these transitions is driven, at least initially, by individual advantage: cooperation paid off for individual foragers, initially through mutualist interaction, then through reciprocation. This argument leads to a reanalysis of the role of violence and the nature of the freeriding threat to cooperation. But the conditions that select for cooperative individuals in the Pleistocene were eroded in the Pleistocene–Holocene transition. So we need an alternative account of the survival, and indeed the expansion, of cooperation in the Holocene. Group selection driven by intercommunal conflict really may well be central to this second transition. (shrink)

The puzzle of resultant moral luck arises when we are disposed to think that an agent who caused a harm deserves to be blamed more than an otherwise identical agent who did not. One popular perspective on resultant moral luck explains our dispositions to produce different judgments with regard to the agents who feature in these cases as a product not of what they genuinely deserve but of our epistemic situation. On this account, there is no genuine resultant moral luck; (...) there is only luck in what evidence becomes available to observers. In this paper, I develop an evolutionary account of our inclination to take the results of actions as evidence for the mental states of agents, thereby explaining why the resulting intuitions are recalcitrant to correction. The account explains why the puzzle of resultant moral luck arises: because our disposition to take the harms agents cause as evidence of their mental states can produce intuitions which conflict with those that arise when we examine agents’ mental states without reference to the results of their actions. The account also helps to solve the puzzle of resultant moral luck, by providing a strong reason to ignore the intuitions caused by our disposition to regard actual harms as evidence of mental states. Since these intuitions arise using an unreliable proxy for agents’ mental states, they ought to be trumped by more reliable evidence. (shrink)

Foot , Hursthouse , and Thompson , along with other philosophers, have argued for a metaethical position, the natural goodness approach, that claims moral judgments are, or are on a par with, teleological claims made in the biological sciences. Specifically, an organism’s flourishing is characterized by how well they function as specified by the species to which they belong. In this essay, I first sketch the Neo-Aristotelian natural goodness approach. Second, I argue that critics who claim that this sort of (...) approach is inconsistent with evolutionary biology due to its species essentialism are incorrect. Third, I contend that combining the natural goodness account of natural-historical judgments with our best account of natural normativity, the selected effects theory of function, leads to implausible moral judgments. This is so if selected effects function are understood in terms of evolution by natural selection, but also if they are characterized in terms of cultural evolution. Thus, I conclude that proponents of the natural goodness approach must either embrace non-naturalistic vitalism or troubling moral revisionism. (shrink)

The goal of forming a science of intentional behavior requires a more richly detailed account of symbolic systems than is assumed by the authors. Cultural systems are not simply the equivalent in the ideational domain of culture of the purported Baldwin Effect in the genetic domain. © 2014 Cambridge University Press.

The evolutionist challenge to moral realism is the skeptical challenge that, if evolution is true, it would only be by chance, a “happy coincidence” as Sharon Street puts it, if human moral beliefs were true. The author formulates Street’s “happy coincidence” argument more precisely using a distinction between probabilistic sensitivity and insensitivity introduced by Elliott Sober. The author then considers whether it could be rational for us to believe that human moral judgments about particular cases are probabilistically sensitive to strongly (...) universal fundamental moral standards of cooperation and fair division. The author provides an explanation of why there would be a benign correlation between human moral judgments in particular cases and the requirements of strongly universal fundamental moral standards. The explanation of the benign correlation is based on group selection for groups of individuals with an egalitarian satisficing psychology and egalitarian norms, because of the ability of such groups to more efficiently solve gene-propagation collective action problems. (shrink)

Cooperation towards public goods relies on credible threats of punishment to deter cheats. However, punishing is costly, so it remains unclear who incurred the costs of enforcement in our evolutionary past. Theoretical work suggests that human cooperation may be promoted if people believe in supernatural punishment for moral transgressions. This theory is supported by new work in cognitive psychology and by anecdotal ethnographic evidence, but formal quantitative tests remain to be done. Using data from 186 societies around the globe, I (...) test whether the likelihood of supernatural punishment—indexed by the importance of moralizing “high gods”—is associated with cooperation. (shrink)

Long before the origins of agriculture human ancestors had expanded across the globe into an immense variety of environments, from Australian deserts to Siberian tundra. Survival in these environments did not principally depend on genetic adaptations, but instead on evolved learning strategies that permitted the assembly of locally adaptive behavioral repertoires. To develop hypotheses about these learning strategies, we have modeled the evolution of learning strategies to assess what conditions and constraints favor which kinds of strategies. To build on prior (...) work, we focus on clarifying how spatial variability, temporal variability, and the number of cultural traits influence the evolution of four types of strategies: (1) individual learning, (2) unbiased social learning, (3) payoff-biased social learning, and (4) conformist transmission. Using a combination of analytic and simulation methods, we show that spatial—but not temporal—variation strongly favors the emergence of conformist transmission. This effect intensifies when migration rates are relatively high and individual learning is costly. We also show that increasing the number of cultural traits above two favors the evolution of conformist transmission, which suggests that the assumption of only two traits in many models has been conservative. We close by discussing how (1) spatial variability represents only one way of introducing the low-level, nonadaptive phenotypic trait variation that so favors conformist transmission, the other obvious way being learning errors, and (2) our findings apply to the evolution of conformist transmission in social interactions. Throughout we emphasize how our models generate empirical predictions suitable for laboratory testing. (shrink)

We propose another positive illusion that fits with McKay & Dennett's (M&D's) criteria for adaptive misbeliefs. This illusion is pervasive in adult reasoning but we focus on its prevalence in children's developing theories. It is a strongly held conviction arising from normal functioning of the doxastic system that confers adaptive advantage on the individual.

Naive physics beliefs can be systematically mistaken. They provide a useful test-bed because they are common, and also because their existence must rely on some adaptive advantage, within a given context. In the second part of the commentary we also ask questions about when a whole family of misbeliefs should be considered together as a single phenomenon.

This article aims at contributing to the discussion about the relationships between ICT, computer science and policy-making by focusing on agent-based social simulation. Enabled, from a technical point of view, by the developments of Distributed Artificial Intelligence in the 1990s and by the features of the object-oriented programming paradigm, agent-based social simulations are a tool for the analysis of social dynamics that can be used also to support the design and the evaluation of public policies. After a brief description of (...) social simulation paradigm and of its impact on social sciences, the paper presents a simple agent-based model devised to analyze, even if in a very abstract way, a phenomenon that can rouse the interest of legal scientists: the interplay between damaging behaviors, punishment and social mechanisms of learning and imitation. Our goal is to show how agent-based simulation can be used not only to illuminate basic mechanisms underlying social phenomena but also to reflect, in an innovative way, on how society can deal with them. (shrink)

The evolution and maintenance of cooperation in human and animal societies challenge various disciplines ranging from evolutionary biology to anthropology, social sciences, and economics. In social interactions, cooperators increase the welfare of the group at some cost to themselves whereas defectors attempt to free ride and neither provide benefits nor incur costs. The problem of cooperation becomes even more pronounced when increasing the number of interacting individuals. Punishment and voluntary participation have been identified as possible factors to support cooperation and (...) prevent cheating. Typically, punishment behavior is unable to gain a foothold in a population, while volunteering alone can efficiently prevent deadlocks in states of mutual defection but is unable to stabilize cooperation. The combined effects of the two mechanisms have surprisingly different consequences in finite and infinite populations. Here we provide a detailed comparison of the two scenarios and demonstrate that driven by the inherent stochasticity of finite populations, the possibility to abstain from social interactions plays a pivotal role, which paves the way for the establishment of cooperation and punishment. (shrink)

Game theory has played a critical role in elucidating the evolutionary origins of social behavior. Sober and Wilson model altruism as a prisoner's dilemma and claim that this model indicates that altruism arose from group selection pressures. Sober and Wilson also suggest that the prisoner's dilemma model can be used to characterize punishment; hence, punishment too originated from group selection pressures. However, empirical evidence suggests that a group selection model of the origins of altruistic punishment may be insufficient. I argue (...) that examining dominance hierarchies and coalition formation in chimpanzee societies suggests that the origins of altruistic punishment may be best captured by individual selection models. I suggest that this shows the necessity of coupling of game-theoretic models with a conception of what our actual social structure may have been like to best model the origins of our own behavior. ‡I would like to thank Zachary Ernst and Emma Marris for their many helpful comments which greatly improved this paper. †To contact the author, please write to: Department of Philosophy, University of Maryland, Skinner Building, College Park, MD 20742; e-mail: [email protected]. (shrink)

This article shows how the social sciences rejected hard determinism by the mid-twentieth century largely on the deontological basis that it is irreconcilable with social justice, yet this rejection came just before a burst of creative development in consequentialist theories of social justice that problematize a facile rejection of determinism on moral grounds, a development that has seldom been recognized in the social sciences. Thus the current social science view of determinism and social justice is antiquated, ignoring numerous common and (...) well-respected arguments within philosophy that hard determinism can be reconciled with a just society. We support this argument by briefly tracing the parallel development of stances on determinism in the social sciences and the deontological-consequentialist debate in philosophy. The article concludes with a brief consideration of deterministic consequentialist ethics, social justice, and the problems of egoism and altruism. (shrink)

This paper defends the position that the supposed gap between biological altruism and psychological altruism is not nearly as wide as some scholars (e.g., Elliott Sober) insist. Crucial to this defense is the use of James Mark Baldwin's concepts of “organic selection”and “social heredity” to assist in revealing that the gap between biological and psychological altruism is more of a small lacuna. Specifically, this paper argues that ontogenetic behavioral adjustments, which are crucial to individual survival and reproduction, are also crucial (...) to species survival. In particular, it is argued that human psychological altruism is produced and maintained by various sorts of mimicry and self-reflection in the aid of both individual and species survival. The upshot of this analysis is that it is possible to offer an account of psychological altruism that is closelytethered to biological altruism without reducing entirely the former to thelatter. (shrink)

Spite (in the biological or evolutionary sense) is behavior that harms others at a cost to the actor. The presence of spite in human and animal populations presents an evolutionary puzzle. Recent work has suggested small populations and pre-play signaling can have a significant effect on the evolution of spite. Here, we use computational methods to explore these factors in fluctuating populations that may go extinct. We find that the presence of spite can make a population significantly more likely to (...) go extinct, but that this does not preclude the possibility of spite reliably evolving. Additionally, we find that the stochastic effects of small fluctuating populations allow for the evolution and predominance of signal-mediated conditional spite across a wide range of conditions. These results suggest that directed harm, even if costly, can play a significant early role in the evolution of social behaviors and this provides a possible origin for punishment. (shrink)

Hypocrites invite moral opprobrium, and charges of hypocrisy are a significant and widespread feature of our moral lives. Yet it remains unclear what hypocrites have in common, or what is distinctively bad about them. We propose that hypocrites are persons who have undermined their claim to moral authority. Since this self-undermining can occur in a number of ways, our account construes hypocrisy as multiply realizable. As we explain, a person’s moral authority refers to a kind of standing that they occupy (...) within a particular moral community. This status is both socially important and normatively precarious. Hence, moral agents are right to be vigilant when it comes to hypocrisy, and are often justified in their outrage when they detect it. We further argue that our view can preserve what is attractive in rival accounts, while avoiding their associated problems. (shrink)

Strong reciprocity has recently been subject to heated debate. In this debate, the “West camp” :231–262, 2011), which is critical of the case for SR, and the “Laland camp” :1512–1516, 2011, Biol Philos 28:719–745, 2013), which is sympathetic to the case of SR, seem to take diametrically opposed positions. The West camp criticizes advocates of SR for conflating proximate and ultimate causation. SR is said to be a proximate mechanism that is put forward by its advocates as an ultimate explanation (...) of human cooperation. The West camp thus accuses advocates of SR for not heeding Mayr’s original distinction between ultimate and proximate causation. The Laland camp praises advocates of SR for revising Mayr’s distinction. Advocates of SR are said to replace Mayr’s uni-directional view on the relation between ultimate and proximate causes by the bi-directional one of reciprocal causation. The paper argues that both the West camp and the Laland camp misrepresent what advocates of SR are up to. The West camp is right that SR is a proximate cause of human cooperation. But rather than putting forward SR as an ultimate explanation, as the West camp argues, advocates of SR believe that SR itself is in need of ultimate explanation. Advocates of SR tend to take gene-culture co-evolutionary theory as the correct meta-theoretical framework for advancing ultimate explanations of SR. Appearances notwithstanding, gene-culture coevolutionary theory does not imply Laland et al.’s notion of reciprocal causation. “Reciprocal causation” suggests that proximate and ultimate causes interact simultaneously, while advocates of SR assume that they interact sequentially. I end by arguing that the best way to understand the debate is by disambiguating Mayr’s ultimate-proximate distinction. I propose to reserve “ultimate” and “proximate” for different sorts of explanations, and to use other terms for distinguishing different kinds of causes and different parts of the total causal chain producing behavior. (shrink)

Humans have a strong sense of who should be punished, when, and how. Many features of these intuitions are consistent with a simple adaptive model: Punishment evolved as a mechanism to teach social partners how to behave in future interactions. Yet, it is clear that punishment as practiced in modern contexts transcends any biologically evolved mechanism; it also depends on cultural institutions including the criminal justice system and many smaller analogs in churches, corporations, clubs, classrooms, and so on. These institutions (...) can be thought of as a kind of ‘exaptation’: a culturally evolved set of norms that exploits biologically evolved intuitions about when punishment is deserved in order to achieve cooperative benefits for social groups. (shrink)

Evolutionary debunking arguments purport to undercut the justification of our moral judgments by showing why a tendency to make moral judgments would evolve regardless of the truth of those judgments. Machery and Mallon (2010. Evolution of morality. In J.M. Doris and The Moral Psychology Research Group (Eds.), The Moral Psychology Handbook (pp. 3-46). Oxford: Oxford University Press) have recently tried to disarm these arguments by showing that moral cognition – in the sense that is relevant to debunking – is not (...) the product of natural selection. Specifically, they present a barrage of increasingly influential challenges against reciprocity-based approaches to moral nativism. In the present paper I defend the nativist account of moral cognition against these criticisms, thereby bolstering the skeptical conclusions of evolutionary debunking arguments. However, Machery and Mallon's critique does successfully highlight several vulnerabilities in Richard Joyce's approach to debunking, suggesting several ways in which it can be revised toward generating a more robust version of the argument. (shrink)

Strong reciprocity is an effective way to promote cooperation. This is especially true when one not only cooperates with cooperators and defects on defectors (second-party punishment) but even punishes those who defect on others (third-party, “altruistic” punishment). Some suggest we humans have a taste for such altruistic punishment and that this was important in the evolution of human cooperation. To assess this we need to look across a wide range of cultures. As part of a cross-cultural project, I played three (...) experimental economics games with the Hadza, who are hunter-gatherers in Tanzania. The Hadza frequently engaged in second-party punishment but they rarely engaged in third-party punishment. Other small-scale societies engaged in less third-party punishment as well. I suggest third-party punishment only became more important in large, complex societies to solve more pressing collective-action problems. (shrink)

Collective action, or the large-scale cooperation in the pursuit of public goods, has been suggested to have evolved through cultural group selection. Previous research suggests that the costly punishment of group members who do not contribute to public goods plays an important role in the resolution of collective action dilemmas. If large-scale cooperation sustained by the punishment of defectors has evolved through the mechanism of cultural group selection, two implications regarding costly punishment follow: (1) that people are more willing to (...) punish defecting group members in a situation of intergroup competition than in a single-group social dilemma game and (2) that levels of “perverse” punishment of cooperators are not affected by intergroup competition. We find confirmation for these hypotheses. However, we find that the effect of intergroup competition on the punishment of defectors is fully explained by the stronger conditionality of punishment on expected punishment levels in the competition condition. (shrink)

Gossip is a subject that has been studied by researchers from an array of disciplines with various foci and methods. We measured the content of language use by members of a competitive sports team across 18 months, integrating qualitative ethnographic methods with quantitative sampling and analysis. We hypothesized that the use of gossip will vary significantly depending on whether it is used for self-serving or group-serving purposes. Our results support a model of gossip derived from multilevel selection theory that expects (...) gossip to serve group-beneficial rules when rewards are partitioned at the group level on a scale that permits mutual monitoring. We integrate our case study with earlier studies of gossip conducted by anthropologists, psychologists, and management researchers. (shrink)

This paper provides a discussion of the role that emotions may play in the justification of punishment. On the expressivist account of punishment, punishment has the purpose of expressing appropriate emotional reactions to wrongdoing, such as indignation, resentment or guilt. I will argue that this expressivist approach fails as these emotions can be expressed other than through the infliction of punishment. Another argument for hard treatment put forward by expressivists states that punitive sanctions are necessary in order for the law (...) to be valid. But this justification of punishment, too, is unconvincing. There are no good reasons to assume that we have to resort to punitive measures in order to vindicate the law. I will then raise the more general worry whether there is any intelligible link at all between moral emotions such as indignation, resentment or guilt and retributive behaviour. I will finally conclude with some sceptical remarks on the moral worth of retribution. (shrink)

In 1961, Ernst Mayr published a highly influential article on the nature of causation in biology, in which he distinguished between proximate and ultimate causes. Mayr argued that proximate causes (e.g. physiological factors) and ultimate causes (e.g. natural selection) addressed distinct ‘how’ and ‘why’ questions and were not competing alternatives. That distinction retains explanatory value today. However, the adoption of Mayr’s heuristic led to the widespread belief that ontogenetic processes are irrelevant to evolutionary questions, a belief that has (1) hindered (...) progress within evolutionary biology, (2) forged divisions between evolutionary biology and adjacent disciplines and (3) obstructed several contemporary debates in biology. Here we expand on our earlier (Laland et al. in Science 334:1512–1516, 2011) argument that Mayr’s dichotomous formulation has now run its useful course, and that evolutionary biology would be better served by a concept of reciprocal causation, in which causation is perceived to cycle through biological systems recursively. We further suggest that a newer evolutionary synthesis is unlikely to emerge without this change in thinking about causation. (shrink)

Change and variation, while inherent to language, might be seen as running counter to human communicative needs. However, variation also gives language the power to convey reliable indexical information about the speaker. This has been argued to play a significant role in allowing the establishment of large communities based on cooperative exchange , although there has been little experimental investigation of the hypothesis. Here I present a preliminary study intended to help fill this gap. Participants played an online team game (...) in which they negotiated anonymously for resources using an artificial language. Players succeeded in using linguistic cues to distinguish between their teammates and their opponents, and displayed between-team variation in the use of the language. (shrink)

Runaway social selection resulting from partner choice may have shaped aspects of human cooperation and complex sociality that are otherwise hard to account for. Social selection is the subtype of natural selection that results from the social behaviors of other individuals. Competition to be chosen as a social partner can, like competition to be chosen as a mate, result in runaway selection that shapes extreme traits. People prefer partners who display valuable resources and bestow them selectively on close partners. The (...) resulting phenotypic covariance between displays and preferences gives fitness advantages to both, creating runaway selection that could shape a whole suite of prosocial traits including altruism, moral capacities, empathy, and theory of mind. Even though they give a net fitness benefit, traits at the endpoint of runaway social selection can have substantial deleterious effects on other traits such as viability, ability to accumulate resources, or vulnerability to mental disorders. Social selection forces arising from self-interested partner choices may be an invisible hand that shaped capacities for commitment, altruism, and other prosocial capacities of the human social brain. (shrink)

The origins of human social cooperation confound simple evolutionary explanation. But from Darwin and Durkheim onward, theorists (anthropologists and sociologists especially) have posited a potential link with another curious and distinctively human social trait that cries out for explanation: religion. This dissertation explores one contemporary theory of the co-evolution of religion and human social cooperation: the signalling theory of religion, or religious signalling theory (RST). According to the signalling theory, participation in social religion (and its associated rituals and sanctions) acts (...) as an honest signal of one’s commitment to a religiously demarcated community and its way of doing things. This signal would allow prosocial individuals to positively assort with one another for mutual advantage, to the exclusion of more exploitative individuals. In effect, the theory offers a way that religion and cooperation might explain one another, but which that stays within an individualist adaptive paradigm. My approach is not to assess the empirical adequacy of the religious signalling explanation or contrast it with other explanations, but rather to deal with the theory in its own terms – isolating and fleshing out its core commitments, explanatory potential, and limitations. The key to this is acknowledging the internal complexities of signalling theory, with respect to the available models of honest signalling and the extent of their fit (or otherwise) with religion as a target system. The method is to take seriously the findings of formal modelling in animal signalling and other disciplines, and to apply these (and methods from the philosophy of biology more generally) to progressively build up a comprehensive picture of the theory, its inherent strengths and weaknesses. The first two chapters outline the dual explanatory problems that cooperation and religion present for evolutionary human science, and surveys contemporary approaches toward explaining them. Chapter three articulates an evolutionary conception of the signalling theory, and chapters four to six make the case for a series of requirements, limitations, and principles of application. Chapters seven and eight argue for the value of formal modelling to further flesh out the theory’s commitments and potential and describe some simple simulation results which make progress in this regard. Though the inquiry often problematizes the signalling theory, it also shows that it should not be dismissed outright, and that it makes predictions which are apt for empirical testing. (shrink)

Using evolutionary game theory, I consider how guilt can provide individual fitness benefits to actors both before and after bad behavior. This supplements recent work by philosophers on the evolution of guilt with a more complete picture of the relevant selection pressures.

This paper examines three ancient traits of religion whose origins likely date back to the Upper Paleolithic: ancestor worship, shamanism, and the belief in natural and animal spirits. Evidence for the emergence of these traits coincides with evidence for a dramatic advance in human social cooperation. It is argued that these traits played a role in the evolution of human cooperation through the mechanism of social scrutiny. Social scrutiny is an effective means of reducing individualism and enhancing prosocial behavior. Religion’s (...) most ancient traits represent an extension of the human social world into the supernatural, thus reinforcing within-group cooperation by means of ever-vigilant spiritual monitors. Believing that the spirits were always watching may have helped reduce the number of non-cooperators within a group while reinforcing group behavioral norms, thus allowing humanlike levels of cooperation to emerge. (shrink)

In a laboratory experiment, we use a public goods game to examine the hypothesis that human subjects use an involuntary eye-detector mechanism for evaluating the level of privacy. Half of our subjects are “watched” by images of a robot presented on their computer screen. The robot—named Kismet and invented at MIT—is constructed from objects that are obviously not human with the exception of its eyes. In our experiment, Kismet produces a significant difference in behavior that is not consistent with existing (...) economic models of preferences, either self- or other-regarding. Subjects who are “watched” by Kismet contribute 29% more to the public good than do subjects in the same setting without Kismet. (shrink)

Adaptationists explain the evolution of religion from the cooperative effects of religious commitments, but which cooperation problem does religion evolve to solve? I focus on a class of symmetrical coordination problems for which there are two pure Nash equilibriums: (1) ALL COOPERATE, which is efficient but relies on full cooperation; (2) ALL DEFECT, which is inefficient but pays regardless of what others choose. Formal and experimental studies reveal that for such risky coordination problems, only the defection equilibrium is evolutionarily stable. (...) The following makes sense of otherwise puzzling properties of religious cognition and cultures as features of cooperative designs that evolve to stabilise such risky exchange. The model is interesting because it explains lingering puzzles in the data on religion, and better integrates evolutionary theories of religion with recent, well-motivated models of cooperative niche construction. (shrink)

Receive free email alerts when new articles cite this article - sign up in the box at the top here right-hand corner of the article or click..

The cultural norms of traditional societies encourage behavior that is consistent with maximizing reproductive success but those of modern post-demographic transition societies do not. Newson et al (2005) proposed that this might be because interaction between kin is relatively less frequent in modern social networks. Assuming that people’s evaluations of reproductive decisions are influenced by a desire to increase their inclusive fitness, they will be inclined to prefer their kin to make fitness-enhancing choices. Such a preference will encourage the emergence (...) of pronatal cultural norms if social networks are dense with kin. Less pronatal norms will emerge if contact between kin makes up a small proportion of social interactions. This article reports evidence based on role-play studies that supports the assumption of the kin influence hypothesis that evaluations of reproductive decisions are influenced by a desire to increase inclusive fitness. It also presents a cultural evolutionary model demonstrating the long-term effect of declining kin interaction if people are more likely to encourage fitness-enhancing choices when interacting with their kin than with nonrelatives. D 2007 Elsevier Inc. All rights reserved. (shrink)

The various behavioral disciplines model human behavior in distinct and incompatible ways. Yet, recent theoretical and empirical developments have created the conditions for rendering coherent the areas of overlap of the various behavioral disciplines. The analytical tools deployed in this task incorporate core principles from several behavioral disciplines. The proposed framework recognizes evolutionary theory, covering both genetic and cultural evolution, as the integrating principle of behavioral science. Moreover, if decision theory and game theory are broadened to encompass other-regarding preferences, they (...) become capable of modeling all aspects of decision making, including those normally considered “psychological,” “sociological,” or “anthropological.” The mind as a decision-making organ then becomes the organizing principle of psychology. (Published Online April 27 2007) Key Words: behavioral game theory; behavioral science; evolutionary theory; experimental psychology; gene-culture coevolution; rational actor model; socialization. (shrink)

Mayr’s distinction between proximate and ultimate explanation is justly famous, marking out a division of explanatory labor in biology. But while it is a useful heuristic in many cases, there are others in which proximate factors play an important role in shaping evolutionary trajectories, and in such cases, each project is sensitive to, and relevant to, the other. This general methodological claim is developed in the context of a discussion of human cooperation, and in particular, in a discussion on the (...) puzzling stability of the social contract over the Pleistocene–Holocene transition. For I argue that while we have a plausible account of the stability of Pleistocene cooperation, the stabilizing factors of the Pleistocene disappear in the Holocene, but cooperation does not. Holocene humans solved many collective action problems; cooperation did not collapse despite the apparent growth of free-riding elites. So the article combines a methodological claim about the interaction of proximate and evolutionary biology with a substantive one about the ecology of human cooperation. (shrink)

Punitive behaviours are often assumed to be the result of an instinct for punishment. This instinct would have evolved to punish wrongdoers and it would be the evidence that cooperation has evolved by group selection. Here, I propose an alternative theory according to which punishment is a not an adaptation and that there was no specific selective pressure to inflict costs on wrongdoers in the ancestral environment. In this theory, cooperation evolved through partner choice for mutual advantage. In the ancestral (...) environment, individuals were in competition to be recruited in cooperative ventures and it was vital to share the benefits of cooperation in a mutually advantageous manner. If individuals took a bigger share of the benefits, their partners would leave them for more interesting partners. If they took a smaller share, they would be exploited by their partners who would receive more than what they had contributed to produce. This competition led to the selection of a sense of fairness, a cognitive adaptation aiming to share equally the benefits of cooperation in order to attract partners. In this theory, punishment is not necessary for the evolution of cooperation. Punitive behaviours are only a way to restore fairness by compensating the victim or penalizing the culprit. Drawing on behavioural economics, legal anthropology, and cognitive psychology, I show that empirical data fit better with this framework than with the theory of group selection. When people punish, they do so to restore fairness rather than to help the group. (shrink)

Experimental studies on punishment have sometimes been over-interpreted not only for the reasons Guala lists, but also because of a frequent conflation of proximate and ultimate explanatory levels that Guala's review perpetuates. Moreover, for future analyses we may need a clearer classification of different kinds of punishment.

The standard theories of cooperation in humans, which depend on repeated interaction and reputation effects among self-regarding agents, are inadequate. Strong reciprocity, a predisposition to participate in costly cooperation and the punishment, fosters cooperation where self-regarding behaviors fail. The effectiveness of socially coordinated punishment depends on individual motivations to participate, which are based on strong reciprocity motives. The relative infrequency of high-cost punishment is a result of the ubiquity of strong reciprocity, not its absence.

In the past decade, experiments on altruistic punishment have played a central role in the study of the evolution of cooperation. By showing that people are ready to incur a cost to punish cheaters and that punishment help to stabilise cooperation, these experiments have greatly contributed to the rise of group selection theory. However, despite its experimental robustness, it is not clear whether altruistic punishment really exists. Here, I review the anthropological literature and show that hunter-gatherers rarely punish cheaters. Instead, (...) they avoid dealing with them and switch to other partners. I suggest that these data are better explained by individual selection, and in particular by partner choice models, in which individuals are in competition to be recruited by cooperative partners. I discuss two apparent problems for partner choice theories: large-scale cooperation and punishments in economic games. I suggest that rather than favouring group selection theory, these two phenomena provide evidence in favour of individual selection: (1) people produce large-scale cooperation through institutions in which punishment is not altruistic but rewarded on an individual basis; (2) punishment in experimental games can be explained without altruism and is indeed often better explained by individual interests. (shrink)